Overview

Solder fatigue is the degradation of solder under cycling loading. This loading can come in several forms (i.e. drop/shock, vibration, temperature cycling) however the majority of solder fatigue in electronics is thermomechanical driven due to temperature cycling. During temperature cycling, stresses are generated in the solder due to coefficient of thermal expansion (CTE) mismatches between the PCB and component. This causes the solder joints to experience non-recoverable deformation that accumulates and leads to degradation and eventual fracture. Much work has been done to characterize the behavior of various solder alloys and develop predictive solder fatigue damage models using a Physics-of-Failure (PoF) approach.